1. Field of the Invention
The present invention relates to a hot plug electronic device. More particularly, the present invention relates to a hot plug electronic device with high using safety and an over-thermal protection device thereof.
2. Description of Related Art
Since a flash memory has features of non-volatile, low power consumption, small size and non-mechanical structure etc., it becomes a widely used storage device recently. Accordingly, various electronic products applying the flash memories are developed by different manufactures, in which a USB flash memory pen drive becomes a popular one. Generally, since a present USB flash memory pen drive has a hot plug function; it becomes popular in the market due to the feature of high utilization convenience thereof.
However, an actual utilization situation is that when the USB flash memory pen drive is hot plugged to a personal computer, at the moment of plugging, an excessive power damping of the USB flash memory pen drive may be occurred, or an excessive low voltage signal may be sneaked into the USB flash memory pen drive, which may cause a damage to an electrostatic discharge (ESD) protection device within the USB flash memory pen drive, and the damage situation is either an open circuit damage or a short circuit damage.
Accordingly, if the damage situation of the ESD protection device is the open circuit damage, now the USB flash memory pen drive is susceptible to electrostatic interference and may be damaged accordingly. Moreover, if the damage situation of the ESD protection device is the short circuit damage, a power supply (generally is 3.3V) of the USB flash memory pen drive may be directly guided to a ground level, so that if the USB flash memory pen drive is plugged into the personal computer for a long time, the USB flash memory pen drive may be over-thermal, and a case thereof may be burned. Moreover, a user trying to pull out the burned USB flash memory pen drive may be scalded, and therefore utilization safety of the USB flash memory pen drive is greatly reduced.